VMS Help CMS, MODIFY, GROUP, Example  *Conan The Librarian (sorry for the slow response - running on an old VAX)

    CMS> MODIFY GROUP TESTS/READ_ONLY "coordinate before changing
    contents"
    %CMS-S-MODIFIED, group DISKX:[PROJECT.CMSLIB]TESTS modified

      This command sets the group TESTS to READ_ONLY. Once the group
      is set to READ_ONLY, the contents cannot be changed.